Cyanid-furnace



R. M. MAJOR.

CYANID FURNACE.

APPLICATION FILED rgs. n. 1920.

153K286, I Patented Aug. 9, 1921.

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PATENT OFFICE.

RALPH MARSHALL MA JOR, 0F BLOOMFIELD, NEW JERSEY, ASSIGNOR TO DRIVER- EARRIS COMPANY, OF HARRISON, NEW JERSEY, A. CORPORATION OF NEW UNITED STATES JERSEY.

CYANID-FURNAOE.

Specification of Letters Patent.

Patented Aug. 9, 1921.

Application filed February 17, 1920. Serial No. 359,280.

To all whom it may concern .1

Be it known that I, RALPH MARSHALL MAJOR, a citizen of the United States, residing at Bloomfield, county of Essex, and State of New Jersey, have invented a certain new and useful Improvement in Cyanid- Furnaces, of which the following is a full, clear, and exact description.

My invention relates to improvements in cyanid furnaces and has for its object to provide a furnace of which the pot shall have a much longer life than pots in. furnaces now in use, and in which the furnace itself shall also have a longer life than furnaces now in use. It further has for its object to produce a cyanid furnace in which there should be a smaller loss of cyanid by hood shall have a longer life and afford greater rotection to workmen, also a furnace whlch will result in a reduction of the damage due to escaping cyanid fumes.

One feature of my invention consists in forming a seal between the hood and the pot, so as to substantially prevent any cyanid from the pot reaching the interior of the furnace. Another feature consists of separate flues leading from the fire chamber and hood respectlvely.- Another feature of my invention consists in the use of a pot formed of an alloy comprising nickel and chromium in connection with a sealed hood and separate fire chamber flue.

In cyanid furnaces as heretofore constructed, the linings. have been of ordinary silicious fire-brick, and the pot has been made of cast iron having a-flange supported by the upper course of bricks forming the lining, a suitable hood beingl provided to which a line is connected, t rough which hood and fine the roducts of combustion from the fire cham er are discharged, and which flue also serves to carry off the unsublimated cyanid vapors. Such iron pots have comparatively short life, and when they are destro ed not only is it necessary to renew the pot but it is also necessary to reline the furnace. When a pot made of a refractory alloy comprising nickel and chromium is substituted for an iron pot, ,the life of the substituted pot is somewhat longer, but not sufiiciently longer to justify the additional expense. I have discovered that combustion. heated lasts longer and is more this is largely due to the fact that cyanid from the pot works back into the fire chamber by dropping through the flue or trickling beneath the rim of the pot so that, in conjunction with the products'of combustion or heat, some very active agent is produced which attacks the exterior of the pot and also the silicious lining of the fire chamber, and have invented a furnace in which the cyanid from the pot can be substantially excluded from the fire chamber so as to increase the life of the pot and the furnace" lining.

I have further discovered that by separating the cyanid fumes from the products of combustion in my improved furnace the cyanid vapors are much less highly heated and, coming in contact with the walls of the hood which are kept cool by the surrounding air, are sublimated to a very considerable extent so that they are largely returned to the pot instead of passing off through the stack with the products of The hood being less highly easily approached by the workmen.

The furnace has various other features of advantage which will be hereinafter- -more particularly pointed out.

The following is a description of an embodiment of my invention, reference being bad to the accompanying drawings, in which,

Figure 1 shows a vertical section through the furnace embodying my invention;

A Fig. 2 is a section on the line 2--2, Fig. 1;

Fig. 3 is a vertical section of a modified forim of furnace embodying my invention, an

Fi 4 is a horizontal section of the same on t e line 44, Fig. 3.

Referring more particularly to the drawings, 1 is a furnace body having a lining 2 of ordinary fire-brick, which, as is well known, is a brick containing silicious material, forming a fire chamber 3.

vTh1s furnace is preferably heated by an oil burner 4 extending into an opening in the furnace wall, so as toheat the pot 5 suspended from the up er end of the furnace wall. This pot 5 is made of a refractory alloy comprising nickel and chromium. The particular alloy which I prefer to use also contains iron. While the proportions may be considerably varied, the composition is preferably about as follows:

Nickel 60 per cent. Chromium 12 Iron 26 Manganese 1.5

6 is a sheet iron hoodhaving a door 7 through which articles to be treated can be introduced to the pot 5 or removed therefrom. To the upper part of this hood is connected a stack 8, which discharges any cyanid vapors which may be created and are not sublimated. In order to provide a seal between the pot and the hood, I may form upon the pot an extension 9, having a sloping surface and an upwardly extending flange 10, within which the bottom of the hood 6 fits, so as to form a seal which will substantially prevent the escape at that point of cyanid and so that no cyanid vapors or material can escape and find their way back into the interior of the furnace.

The fire chamber of the furnace is provided with a flue 11, which is entirely separated from the space above the pot 5 and the hood 6 and acts to discharge the products of combustion of the fire chamber into the external atmosphere.

The form shown in Fig. 3 is the preferred form. It is similar to the others except that the pot 5 is of ordinary form, having a horizontal flange 12 and the upper course of the furnace wall 13 is made of some neutral material, such as a tamped layer of chrome ore, above which is placed a seal 14 of basic material sloping downward toward the interior of the pot 5. The seal let acts to close the space between the hood and the flange 12, so as to prevent the downward passage of any melted or vaporized cyanid at that point. The sloping surface referred to guides any cyanid which may be sublimated within the hood into the pot.

In both of these forms all or substantially all cyanid within the pot is prevented from ever entering the fire chamber of the furnace, with the result that the exterior of the pot is never subjected to the action of the destructive gases which would be produced by the entrance of the cyanid into the fire chamber, and so that the inner walls of the furnace are also never subjected to such action. By the exclusion of the cyanid from the fire-chamber the life of the pot is greatly extended and the life of the furnace lining is also greatly extended. This substantial exclusion of the cyanid from the pot is brought about by the provision of a sepa rate and independent flue for the products of combustion, as distinguished from the use of a single flue to discharge both the cyanid fumes from the hood and the products of combustion, which use heretofore prevented cyanid working backward into the fire-pot, and also by the provision of a seal between the hood and a fire-pot, which will prevent cyanid from working into the fire chamber by passing beneath the flange of the pot.

In the furnace of Figs. 3 and 4, the basic seal 14: is preferably of tar, slag and magnesite molded and tamped into place. This being basic is not attacked by the cyanid. It is necessary, however, to separate the basic seal from the acid fire-bricks with which the furnace is lined. since otherwise one would act upon the other in the presence of the intense heat of the furnace. This separation is attained by the layer of chrome ore which is so neutral as not to be affected by either the basic or acid materials contacting therewith.

By using the chrome ore or other neutral separator the furnace can be lined with ordinary fire-brick as distinguished from the more expensive magnesite or other basic brick which would otherwise be necessary if the furnace lining contacted with a basic seal.

The cyanid bath used is the ordinary or commercial bath commonly employed, 76% sodium cyanid and 24% sodium chlorid.

As will be evident to those skilled in the art, my invention permits of various modifications without departing from the spirit thereof or the scope of the appended claims.

What I claim is:

l. The combination of a refractory cyanid pot, a furnace for heating the same, a hood for said pot substantially preventing cyanid from said pot entering the interior of said furnace, a flue for said hood and a flue for the products of combustion of said flurnace independent of said hood and its 2. The combination of a refractory cyanid pot, a furnace for heating the same, a hood for said not substantially preventing cyanid from said pot entering the interior of said furnace, a'fiue for said hood, a flue for the products of combustion of said furnace independent of said hood and its flue. and a basic seal between said hood and said pot.

3. The combination of a refractory cyanid pot, a furnace for heating the same, a hood for said pot substantially preventing cyanid from said pot entering the interior of said furnace, a flue for said hood, a flue for the products of combustion of said furnace independent of said hood and its flue, said furnace having a wall composed of acid materials, a basic seal between said hood and said pot, and a neutral layer between said seal and said furnace wall.

at. The combination of a refractory cyanid pot, a furnace for heating the same, a hood for said pot substantially preventing cyanid from said pot entering the interior of said furnace, a flue for the products of combustion of said furnace, independent of said hood, and a basic seal between said hood and said pot, said seal having a surface sloping toward the pot. a

5. The combination of a refractory cyanid pot, a furnace for heating the same, a hood confining the fumes from said pot so as to substantially prevent the cyanid from said furnace entering the fire chamber of said furnace; said hood being exposed to a cooling medium and acting to sublimate cyanid fumes rising from said pot, and a flue for the products of combustion of said furnace independent of said hood.

6. The combination of a refractory cyanid pot, a furnace for heating the same, a

hood for said pot substantially preventing cyanid from said pot entering the interior of said furnace, a flue for said hood, and a flue for the products of combustion of said furnace independent of said hood and its flue, said pot being composed of an alloy comprising chromium.

7. The combination of a refractory cyanid pot, a furnace for heating the same, a.

RALPH MARSHALL MAJOR. 

